A light adjustable lens is an optical device whose refractive properties can be changed after its fabrication and insertion into a human eye. Light adjustable lenses can have a refraction modulating composition dispersed in a polymer matrix. After the lens has been implanted into the eye and refractive stabilization has occurred, the preexisting optical aberrations or those induced by the surgical procedure are measured. In order to correct these optical aberrations (e.g., spherical power, astigmatism, spherical aberration, etc.), a corresponding amount of UV-Vis radiation is applied to the light adjustable lens, which alters the optical properties of the lens either through changes in its shape, its index of refraction, or both. Following one or several irradiations in which portions of the lens have been exposed to selectively and spatially modify the refractive power, the entire lens is irradiated to “lock in” the modified lens.
Prior work describes the use of UV irradiation (320-400 nm) for post-operative power adjustment of light adjustable lenses. For example, a Helium Cadmium (HeCd) laser operating at 325 nm and a mercury (Hg) arc lamp spectrally filtered for the emission lines at 334 and 365 nm have been used for modifying the refractive power of light adjustable lenses. Additionally, the prior work also mentions tripled frequency laser diode pumped solid state YAG laser operating at 355 nm, an argon ion laser operating in between 350-360 nm, a deuterium discharge lamp, and broad band xenon:mercury lamps operating with any narrow band spectral filter are useful sources for conducting UV irradiation tests on light adjustable materials and lenses.
However, there are potential safety issues related to each of these sources. Coherent sources (e.g., lasers) are narrowly focused and have high irradiances that can cause permanent damage to retinal tissues. In addition, such sources must be rasterized across the lens requiring complex control of the beam and increased cost. Extended or more diffuse, incoherent sources such as arc lamps offer a more attractive solution from the standpoint of economic (cost and availability) and safety concerns (coherent vs. non-coherent) but they must be attenuated by as much as a factor of 1000 for use in irradiating the light adjustable lenses. Thus, improper use of the lamp, mechanical, or electrical failure could result in applying high irradiances and radiant exposures to the ocular structures causing damage. Taken together, there remains a need in the art for methods to modify the lens so as to increase the achieved power change, reduce the dose required for lock-in, and improve the retinal safety profile of the procedure.
U.S. Pat. No. 9,895,467 discloses the use of upconverting nanocrystals for use in intraocular lenses. While this use provides substantial benefits, there still remains room for improvement. For example, while single crystal upcconverting nanoparticles described therein to emit at wavelenths suitable for activating the photoinitiators described therein, these emissions tend to be weak, resulting in low quantum yields. The present disclosure addresses these and other concerns.